Rapid Lipid Content Screening in <em>Neochloris oleoabundans</em> Utilizing Carbon-Based Dielectrophoresis

• Main Authors: Cynthia M. Galicia-Medina, Matías Vázquez-Piñón, Gibran S. Alemán-Nava, Roberto C. Gallo-Villanueva, Sergio O. Martínez-Chapa, Marc J. Madou, Sergio Camacho-León, Jonathan S. García-Pérez, Diego A. Esquivel-Hernández, Roberto Parra-Saldívar, Víctor H. Pérez-González
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Micromachines
• Subjects: dielectrophoresis; microalgae; biofuel; microfluidics; carbon-microelectromechanical systems
• Online Access: https://www.mdpi.com/2072-666X/12/9/1023

In this study, we carried out a heterogeneous cytoplasmic lipid content screening of Neochloris oleoabundans microalgae by dielectrophoresis (DEP), using castellated glassy carbon microelectrodes in a PDMS microchannel. For this purpose, microalgae were cultured in nitrogen-replete (N+) and nitrogen-deplete (N−) suspensions to promote low and high cytoplasmic lipid production in cells, respectively. Experiments were carried out over a wide frequency window (100 kHz–30 MHz) at a fixed amplitude of 7 V_PP. The results showed a statistically significant difference between the dielectrophoretic behavior of N+ and N− cells at low frequencies (100–800 kHz), whereas a weak response was observed for mid- and high frequencies (1–30 MHz). Additionally, a finite element analysis using a 3D model was conducted to determine the dielectrophoretic trapping zones across the electrode gaps. These results suggest that low-cost glassy carbon is a reliable material for microalgae classification—between low and high cytoplasmic lipid content—through DEP, providing a fast and straightforward mechanism.